The accurate simulation of regional-scale winter wheat yield is important for national food security and the balance of grain supply and demand in China.Presently,most remote sensing process models use the“biomass...The accurate simulation of regional-scale winter wheat yield is important for national food security and the balance of grain supply and demand in China.Presently,most remote sensing process models use the“biomass×harvest index(HI)”method to simulate regional-scale winter wheat yield.However,spatiotemporal differences in HI contribute to inaccuracies in yield simulation at the regional scale.Time-series dry matter partition coefficients(Fr)can dynamically reflect the dry matter partition of winter wheat.In this study,Fr equations were fitted for each organ of winter wheat using site-scale data.These equations were then coupled into a process-based and remote sensingdriven crop yield model for wheat(PRYM-Wheat)to improve the regional simulation of winter wheat yield over the North China Plain(NCP).The improved PRYM-Wheat model integrated with the fitted Fr equations(PRYM-Wheat-Fr)was validated using data obtained from provincial yearbooks.A 3-year(2000-2002)averaged validation showed that PRYM-Wheat-Fr had a higher coefficient of determination(R^(2)=0.55)and lower root mean square error(RMSE=0.94 t ha^(-1))than PRYM-Wheat with a stable HI(abbreviated as PRYM-Wheat-HI),which had R^(2) and RMSE values of 0.30 and 1.62 t ha^(-1),respectively.The PRYM-Wheat-Fr model also performed better than PRYM-Wheat-HI for simulating yield in verification years(2013-2015).In conclusion,the PRYM-Wheat-Fr model exhibited a better accuracy than the original PRYM-Wheat model,making it a useful tool for the simulation of regional winter wheat yield.展开更多
[Objectives]This study was conducted to investigate the effects of slow-release nitrogen fertilizer on dry matter accumulation and translocation of summer maize.[Methods]With Zhoudan 9 as the test variety,six differen...[Objectives]This study was conducted to investigate the effects of slow-release nitrogen fertilizer on dry matter accumulation and translocation of summer maize.[Methods]With Zhoudan 9 as the test variety,six different treatment were set up:blank control(CK1),slow-release urea 75 kg/hm^(2)(C1),slow-release urea 150 kg/hm^(2)(C2),slow-release urea 225 kg/hm^(2)(C3),slow-release urea 300 kg/hm^(2)(C4)and ordinary urea 300 kg/hm^(2)(CK2),to study the change law of dry matter accumulation and translocation in summer maize.[Results]Treatment slow-release urea 225 kg/hm^(2)(C4)showed summer maize yield,dry matter translocation between organs,grain contribution rate and proportion of grain dry matter in the full ripe stage higher than other treatments.Considering the weight loss and cost factors,slow-release urea 225 kg/hm^(2)(C3)could be recommended as the fertilizing amount for summer maize.[Conclusions]This study provides theoretical reference for rational selection of fertilizers for reducing fertilizer application and increasing fertilizer efficiency,and for production of summer maize in Shajiang black soil region.展开更多
Lodging is a critical constraint to yield increase.There appear to be tradeoffs between yield formation and lodging resistance in maize.Hypothetically,it is feasible to reduce lodging risk as well as increase grain yi...Lodging is a critical constraint to yield increase.There appear to be tradeoffs between yield formation and lodging resistance in maize.Hypothetically,it is feasible to reduce lodging risk as well as increase grain yield by optimizing dry-matter allocation to different organs under different environments.A three-year field experiment was conducted using four maize cultivars with differing lodging resistances and five growing environments in 2018–2020.Lodging-susceptible(LS)cultivars on average yielded more than lodging-resistant(LR)cultivars when lodging was not present.The yield components kernel number per ear(KN)and thousand-kernel weight(TKW)were both negatively correlated with lodging resistance traits(stalk bending strength,rind penetration strength,and dry matter weight per internode length).Before silking,the LR cultivar Lishou 1(LS1)transported more assimilates to the basal stem,resulting in a thicker basal stem,which reduced dry matter allocation to the ear and in turn KN.The lower KN of LS1 was also due partly to the lower plant height(PH),which increased lodging resistance but limited plant dry matter production.In contrast,the LS cultivars Xianyu 335(XY335)and Xundan 20(XD20)produced and allocated more photoassimilates to ears,but limited dry matter allocation to stems.After silking,LS cultivars showed higher TKW than LR cultivars as a function of high photoassimilate productivity and high assimilate allocation to the ear.The higher lodging resistance of LS1 was due mainly to the greater assimilate allocation to stem after silking and lower PH and ear height(EH).High-yielding and high-LR traits of Fumin(FM985)were related to optimized EH and stem anatomical structure,higher leaf productivity,low assimilate demand for kernel formation,and assimilate partitioning to ear.A high presilking temperature accelerated stem extension but reduced stem dry matter accumulation and basal stem strength.Post-silking temperature influences lodging resistance and yield more than other environmental factors.These results will be useful in understanding the tradeoffs between KN,KW,and LR in maize and environmental influences on these tradeoffs.展开更多
The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumul...The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumulation and nutrient quality of maize were systematically studied by field experiments and instrumental analysis using maize varieties of different maturities as test materials.The results showed that the accumulation of dry matter was enhanced by an increased dosage of a dehydrating agent.When the dehydrating agent dosage reached 1800 mL•hm-2,the dry matter accumulation of early-maturing varieties increased by 24.1 g,and the water content decreased by 8.08%.Different maize varieties were treated with the same dose;early-maturing varieties showed significant effects on grain dry matter accumulation,and kernel dry matter accumulation increased by 7%.The effects of different doses on grain dehydration were obvious,and the effects on different maize varieties varied.Medium-ripening maize varieties showed the most significant effect,with a 19.5%reduction in water content.The effects of dehydrating agent doses on maize yield,grain nutrient quality and seed germination rate were not significant.Therefore,a dehydrating agent promoted the accumulation of dry matter in grain and accelerated the rapid dehydration.展开更多
Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangel...Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangeland on relative frequency, dry matter yield and nutritive value of dominant grasses in an area invaded by Euryops floribundus. A plot of 2.5 ha was measured and the boundaries demarcated using tape measure and steal pins, the plot was further divided into two subplots of 1ha each which were 5 m apart. One subplot was fenced and protected from grazing livestock, while one subplot was grazed continuously and not fenced. Three parallel belt transects of 100 m × 2 m with 3 m apart were laid out in both subplots. Woody plants occurring within the transects were identified and recorded to determine density. In each subplot, a 0.25 m<sup>2</sup> quadrant measuring was thrown randomly to take detailed records on plant species, relative frequency of species and herbage biomass. Four dominant species at the two sites were harvested to determine the nutritive value. Results indicate that grazing exclusion (GE) facilitates grass species diversity, subsequently sixteen and thirteen grasses species were recorded in the GE and uncontrolled grazed (UG) sites, respectively. Eragrostis chloromelas (21.7%), and Themeda triandra (13.2%) had high relative frequencies in the GE site. Highest biomass production was recorded in the GE site (1400 kg·ha<sup>-1</sup>) compared to UG site (1102 kg·ha<sup>-1</sup>). Crude protein content was relatively lower at UG site (5.4% - 5.8%) as compared to GE site (7.2% - 7.8%). It was concluded that, GE showed a positive impact on a relative frequency (%), dry matter yield and crude protein content. UG creates a conducive environment for Euryops recruitment. Further studies are required to examine the impact of GE in long-term trial setup.展开更多
Landscape urbanization broadly affects ecosystems in coastal watersheds, but, until now, the influence of nonpoint source urban inputs on dissolved organic matter (DOM) amount, composition, and source is poorly unders...Landscape urbanization broadly affects ecosystems in coastal watersheds, but, until now, the influence of nonpoint source urban inputs on dissolved organic matter (DOM) amount, composition, and source is poorly understood. To understand how DOM composition varied with urbanization, fluorescence excitation-emission matrices (EEMs) were determined for urban and non-urban waters from upstream to downstream sites along three adjacent coastal watersheds that flow into the Mediterranean Sea. Two humic DOM fluorescent components (humic-like and fulvic-like peaks) and two proteinic components (tyrosine-like and tryptophane-like peaks) were identified by EEM fluorescence. The results indicated that urbanization had an important influence on DOM concentration and composition, with urban waters having a high degree of DOM variation due to different land uses surrounding each body of water. Urban waters show a higher DOM fluorescence index (FI), the highest fluorescence intensity of protein-like manifested also by BIX values, and a lower value of the humification index (HIX) than non-urban waters which were dominated by allochthonous inputs. In addition, the EEM was compared in dry and wet season where higher DOM amounts and FI appeared in summer due to autochthonous production coming from algae growth compared to allochthonous input from rainfall dominated in wet season. The concentration of DOC increased from upstream to downstream for the three rivers, especially Beirut River. The increase in DOC values was observed in both dry and wet seasons by 39 and 19 times respectively compared to upstream (0.93 - 0.91 mgC/L).展开更多
The pictures from the James Webb Space Telescope (JWST) suggest that massive galaxies were already at the beginning of the expansion of the Universe because there was too short time to create them. It is consistent wi...The pictures from the James Webb Space Telescope (JWST) suggest that massive galaxies were already at the beginning of the expansion of the Universe because there was too short time to create them. It is consistent with the new cosmology presented within the Scale-Symmetric Theory (SST). The phase transitions of the initial inflation field described in SST lead to the Protoworld—its core was built of dark matter (DM). We show that the DAMA/LIBRA annual-modulation amplitude forced by the change of the Earth’s velocity (i.e. baryonic-matter (BM) velocity) in relation to the spinning DM field in our Galaxy’s halo should be very low. We calculated that in the DM-BM weak interactions are created single and entangled spacetime condensates with a lowest mass/energy of 0.807 keV—as the Higgs boson they can decay to two photons, so we can indirectly detect DM. Our results are consistent with the averaged DAMA/LIBRA/COSINE-100 curve describing the dependence of the event rate on the photon energy in single-hit events. We calculated the mean dark-matter-halo (DMH) mass around quasars, we also described the origin of the plateaux in the rotation curves for the massive spiral galaxies, the role of DM-loops in magnetars, the origin of CMB, the AGN-jet and galactic-halo production, and properties of dark energy (DE).展开更多
[Objective] The aim of the research was to find the optimal nitrogen application rate, density and seedling age for no-tillage rape in seedling stage. [Method] With the D-optimal quadratic regression design for three ...[Objective] The aim of the research was to find the optimal nitrogen application rate, density and seedling age for no-tillage rape in seedling stage. [Method] With the D-optimal quadratic regression design for three factors, the 310 scheme was designed to study the effects of nitrogen application rate, density and seedling age on dry matter accumulation of no-tillage rape in seedling stage. [Result] With the increase of nitrogen application rate, density and seedling age, the dry matter content appeared like a parabola, increasing firstly and then declining. The change of nitrogen application rate caused greater influence than that of density and seedling age; the interaction effects between nitrogen application rate and density were greater than that between nitrogen application rate and seedling age as well as between density and seedling age. [Conclusion] Considered comprehensively, the dry matter content of no-tillage rape in seedling stage reached the highest level (4 768.2 kg/hm2) when the nitrogen application rate, the density and the seedling age were 195 kg/hm2, 93 000 plants/hm2 and 33 d, respectively.展开更多
In this paper, the effect of different fertilizer treatments on the main indexes of growth and development and dry matter accumulation of perennial mulberry, which is cut and pruned in summer, were studied with ‘3414...In this paper, the effect of different fertilizer treatments on the main indexes of growth and development and dry matter accumulation of perennial mulberry, which is cut and pruned in summer, were studied with ‘3414’ field experiment design. The results showed that N, P, and K at proper amounts could promote mulberry growth and development, improve its dry matter content, increase its dry matter accumulation. The effects of N, P, K on leaf yield per plant were respectively expressed as follows: N2 N3 N1 N0 , P2 P1 P3 P0 , K2 K1 K3 K0 . It can be concluded that the recommended fertilizer amounts of dry matter accumulations in mulberry leaf were 694.36 kg/hm2 of N, 198.15 kg/hm2 of P, and 274.26 kg/hm2 of K and the dry matter achieved the maximum at 8 045.04 kg/hm2 . The recommended fertilizer amounts of accumulated dry matter in branch were 1 000.05 kg/hm2 of N, 242.04 kg/hm2 of P, and 218.01 kg/hm 2 of K, and the dry matter achieved the maximum at 5 969.05 kg/hm2 . The recommended fertilizer amount in young shoots were 883.76 kg/hm2 of N, 204.48 kg/hm2 of P and 426.59 kg/hm2 of K and dry matter achieved the maximum at 1 410.24 kg/hm2 . This paper could provide reference for the construction of highly-qualified mulberry field in Sichuan hilly area.展开更多
[Objective] This study was conducted to investigate the effects of application modes of potassium fertilizer on sorghum grain yield and dry matter accumulation. [Method] Sorghum hybrids Jiza 305 and Jiza 87 were used ...[Objective] This study was conducted to investigate the effects of application modes of potassium fertilizer on sorghum grain yield and dry matter accumulation. [Method] Sorghum hybrids Jiza 305 and Jiza 87 were used as materials, and four treatments were designed (Ko: applying potassium at 0 kg/hm^2, K1: applying potassium as base fertilizer at 120 kg/hm^2, K2: applying potassium as base fertilizer at 90 kg/hm^2 and as additional fertilizer at 30 kg/hm^2, and K3: applying potassium as base fertilizer at 60 kg/hm^2 and as additional fertilizer at 60 kg/hm^2) to investigate the effects of application modes of potassium fertilizer on dry matter accumulation and grain yield, so as to determine the best application mode of potassium fertilizer. [Result] The results showed that after the application of potassium, the leaf area, dry matter accumulation, grain starch content, yield and economic coefficient of sorghum plants were improved. The leaf area values of the two sorghum cultivars showed the order of K0〈K1〈K2〈K3. The economic coefficients were in order of K0〈 K3〈K2〈K1. The amounts of dry matter accumulation, grain starch contents and grain yields showed the order of K0〈K3〈K1〈K2. For Jiza 305, the grain yields of K1, K2 and K3 were higher than that of Ko by 9.3%, 15.6% and 9.3%, respectively. As to Jiza 87, the grain yields of K1, K2 and K3 were higher than that of K0 by 8.1%, 12.5% and 8.1%, respectively. [Conclusion] Comprehensively, the best application method was 90 kg of potassium as base fertilizer and 30 kg of potassium as additional fertilizer per hectare.展开更多
Using three orange-fleshed sweetpotato varieties as experimental materials,16 economic traits at 60 d,75 d,90 d,105 d,120 d and 135 d after planting were measured,so as to revealing the dynamic variations of β-carote...Using three orange-fleshed sweetpotato varieties as experimental materials,16 economic traits at 60 d,75 d,90 d,105 d,120 d and 135 d after planting were measured,so as to revealing the dynamic variations of β-carotene and dry matter accumulation in roots and their relationships with economic traits in orangefleshed sweetpotato.The results showed that the dynamic variations of β-carotene accumulation in tubers varied hugely among different varieties.Interesting,the βcarotene content of all three varieties showed a significant decrease after 120 d,while the dry matter content of them performed a similar "fluctuation-type".Correlation analysis indicated that β-carotene content of three orange-fleshed sweetpotato varieties had no significant correlation with dry matter content and photosynthetic parameters,but the correlation with other economic traits also varied among varieties.展开更多
To clarify the effects of mechanical sowing and transplanting on dry mat- ter production of middle-season hybrid rice, a two-factor split plot design was used to study the effects of different sowing and transplanting...To clarify the effects of mechanical sowing and transplanting on dry mat- ter production of middle-season hybrid rice, a two-factor split plot design was used to study the effects of different sowing and transplanting methods and their interac- tion with the seedling number per hill or seeding time on dry matter accumulation, distribution and transformation of F You 498, a middle-season hybrid rice variety, under field conditions in 2012 and 2013. The results showed that there was a marked effect of the sowing and transplanting methods and their interaction with the seedling number per hill or seeding time on dry matter accumulation, distribution and transformation. The total population dry matter accumulation of the treatments with mechanical direct seeding (MDS) and machine-based transplanting (MT) was lower than that of the treatment with traditional manual transplanting (TMT). How- ever, MDS had higher dry matter accumulation and accumulating rate in the joint- ing-earing stage,and maintained higher stem-sheath exportation, export rate and transformation than MT and TMT; MT had higher dry matter accumulation and ac- cumulating rate in the heading-maturity period than MDS and TMT. Moreover, the treatments with low seedling number per hill or early seeding enhanced the assimi- lation of dry matter after heading,the ratio of dry matter accumulation after earing to biomass yield and the contribution rate of dry matter accumulation after earing, and a reasonable early sowing was favorable to increase the harvest index of middle- season hybrid rice under mechanical sowing and transplanting conditions.展开更多
[Objective] This study aimed to investigate the growth and development and dry matter production and allocation of greenhouse tomato in North China. [Method] With tomato cultivar 'Jinguo No.l' as the experimental ma...[Objective] This study aimed to investigate the growth and development and dry matter production and allocation of greenhouse tomato in North China. [Method] With tomato cultivar 'Jinguo No.l' as the experimental material, the ex- periments were conducted in a solar greenhouse located in Taigu, Shanxi (37o25' N, 112o25' E) from March to July, in 2014 and 2015. [Result] The plant height, leaf number, leaf area and dry matter production of greenhouse tomato increased lin- early with the increased days after transplantation, and their growth rates were 2.74 cm/d, 0.32 leaf/d, 70 cm2/d and 9.4 g/(m2.d), respectively. The fruit dry weight also showed a linear relationship with the plant dry weight. After fruit setting, the fruit dry weight was increased by about 0.69 g when the plant dry weight was increased by 1 g. The allocation proportions of dry matter in tomato roots, stems and leaves de- clined significantly from plant flowering to fruiting, while the proportion of fruit dry weight in plant dry weight increased significantly, exceeding 60%. There was a strong linear relationship between dry matter production of tomato and effective cu- mulative temperature (sum of temperature higher than 10 ^(3) in the solar green- house, and the dry matter production was increased by about 0.73 g/m2 when the effective cumulative temperature was increased by one unit. The dry matter produc- tion of tomato plant also showed a strong linear relationship with photosynthetic ac- tive radiation (PAR) in the greenhouse, and about 3.4 g of dry matter was synthe- sized per unit (M J) of PAR. [Conclusion] Extending the growing period and improv- ing the temperature and light conditions could increase the dry matter production of tomato.展开更多
[Objective] This study aimed to investigate the effects of different planting and irrigation patterns on water consumption characteristics and dry matter produc- tion and allocation of winter wheat. [Method] With high...[Objective] This study aimed to investigate the effects of different planting and irrigation patterns on water consumption characteristics and dry matter produc- tion and allocation of winter wheat. [Method] With high-yield winter wheat cultivar Jimai 22 as the experimental material, field experiment was conducted during 2008- 2010. A total of 3 planting patterns were designed, uniform row, wide-narrow row and furrow. Under each planting pattern, total four irrigation patterns were designed, no irrigation (Wo), irrigation at jointing state (Wl), irrigation at jointing and anthesis stages (W2) and irrigation at jointing, anthesis and milking stages (W3), and the irri- gation amount per treatment was all 60 mm. [Result] Under the three planting pat- terns, with the increased irrigation amount, the total water consumption of the exper- imental field increased; the proportion of irrigation in the total water consumption in- creased, and that of soil water consumption in the total water consumption de- creased significantly. Compared with W0 treatment, various irrigation treatments sig- nificantly increased the post-anthesis dry matter accumulation in wheat plants; with the increased irrigation amount, the grain yield under the three planting patterns all increased, while the water use efficiency (WUE) decreased. Under the same irriga- tion conditions, compared with other two planting patterns, furrow planting increased the total water consumption of the experimental field, increased the proportion of soil water consumption in the total water consumption, and improved the WUE and wheat grain yield. [Conclusion] Under the experimental conditions, considering both wheat grain yield and WUE, furrow planting with moderately deficit irrigation at joint- ing and anthesis stages is more suitable for the winter wheat production in North China Plain.展开更多
In order to select the suitable soil for transplanting tobacco in Hunan to- bacco growing areas, pot experiment was conducted to study the effects of different transplanting nutdent soils on the growth and dry matter ...In order to select the suitable soil for transplanting tobacco in Hunan to- bacco growing areas, pot experiment was conducted to study the effects of different transplanting nutdent soils on the growth and dry matter accumulation of tobacco. The results indicated that the treatments of transplanting with nutrition soils were better than the control group. For the underground part, transplanting nutrient soil could effectively improve the root activity of tobacco plants, and increase root volume, root surface area, total root length, as well as the number of root tips and the number of root branches. For the aboveground part, transplanting nutrient soil could remarkably improve the plant height, stem girth, leaf number and maximum leaf area, and could simultaneously significantly increase the dry matter accumulation. By comparison, peat + mushroom residue + saw dust + straw powder + bicchar + root promoting nutrient solution was the most effective treatment, and the effect of sole application of nutrient solution was limited. In conclusion, transplanting with nutrition soil could effectively promote the growth and dry matter accumulation of tobacco.展开更多
[Objective] The aim was to discuss the group dry matter accumulation and economic benefits under the patterns of intercropping maize (Zea mays L.) with soy-bean [Glycine max (L.) Merril ]. [Methods] Zhengdan-958 a...[Objective] The aim was to discuss the group dry matter accumulation and economic benefits under the patterns of intercropping maize (Zea mays L.) with soy-bean [Glycine max (L.) Merril ]. [Methods] Zhengdan-958 and Luhuang-1 were used as the testing breeds to study the effects of intercropping patterns on dry matter accumulation and transportation of maize and soybean in Huang-huai-hai. [Results] For maize, the dry matter accumulation amounts per hectare of intercropping was significant higher than that of the monoculture patterns, especial y after silking, when it reached extremely level; while for soybean, the dry matter accumulation amounts before flowering and after flowering of monocropping were al significantly higher than that of the intercropping patterns. For both maize and soybean, the transfer amounts of monocropping were al significantly or extremely significantly higher than that of intercropping; and the transfer ratio of maize intercropping was 0.59% higher than that of maize monocropping, while for soybean, it was 4.74% higher. Fitted dry matter accumulation with Logistic equation, it showed that the difference in maximum dry matter accumulation rate between maize monocropping and intercropping reached significant level, while for soybean, the maximum dry matter accumulation rate and its appearance time as wel as duration time between intercropping and monocropping were al reached significant level. The total land equivalent ratio of intercropping was 1.30. From yield and output value, the total yield of intercropping were 10.97 t/hm2, 0.64% and 326.85% higher than monocropping of maize and soy-bean, respectively. The total output value of intercropping was 25 796.23 yuan/hm2, respectively 12.67% and 104.68% higher than of maize and soybean monocropping. [Conclusion] The study lays a basis for improving grain yield and economic benefits.展开更多
Spring wheat (Triticum aestivum L. cv. Dingxi No. 8654) was treated with twoconcentrations of atmospheric CO_2 (350 and 700 μmol mol^(-1)), two levels of soil moisture(well-watered and drought) and five rates of nitr...Spring wheat (Triticum aestivum L. cv. Dingxi No. 8654) was treated with twoconcentrations of atmospheric CO_2 (350 and 700 μmol mol^(-1)), two levels of soil moisture(well-watered and drought) and five rates of nitrogen fertilizer (0, 50, 100, 150, and 200 mgkg^(-1) soil) to study the atmospheric CO_2 concentration effect on dry matter accumulation and Nuptake of spring wheat. The effects of CO_2 enrichment on the shoot and total mass depended largelyon soil nitrogen level, and the shoot and total mass increased significantly in the moderate to highN treatments but did not increase significantly in the low N treatment. Enriched CO_2 concentrationdid not increase more shoot and total mass in the drought treatment than in the well-wateredtreatment. Thus, elevated CO_2 did not ameliorate the depressive effects of drought and nitrogenstress. In addition, root mass decreased slightly and root/shoot ratio decreased significantly dueto CO_2 enrichment in no N treatment under well-watered condition. Enriched CO_2 decreased shoot Ncontent and shoot and total N uptake; but it reduced root N content and uptake slightly. Shootcritical N concentration was lower for spring wheat grown at 700 μmol mol^(-1) CO_2 than at 350μmol mol^(-1) CO_2 in both well-watered and drought treatments. The critical N concentrations were16 and 19 g kg^(-1) for the well-watered treatment and drought treatment at elevated CO_2 and 21 and26 g kg^(-1) at ambient CO_2, respectively. The reductions in the movement of nutrients to theplant roots through mass flow due to the enhancement in WUE (water use efficiency) and the increasein N use efficiency at elevated CO_2 could elucidate the reduction of shoot and root Nconcentrations.展开更多
Climate change is recognized to increase the frequency and severity of extreme temperature events. At flowering and grain filling stages, risk of high temperature stress (HTS) on rice might increase, and lead to dec...Climate change is recognized to increase the frequency and severity of extreme temperature events. At flowering and grain filling stages, risk of high temperature stress (HTS) on rice might increase, and lead to declining grain yields. A regulated cabinet experiment was carried out to investigate effects of high temperature stress on rice growth at flowering and grain- filling stages. Results showed that no obvious decrease pattern in net photosynthesis appeared along with the temperature rising, but the dry matter allocation in leaf, leaf sheath, culm, and panicle all changed. Dry weight of panicle decreased, and ratio of straw to total above ground crop dry weight increased 6-34% from CK, which might have great effects on carbon cycling and green house gas emission. Grain yield decreased significantly across all treatments on average from 15 to 73%. Occurrence of HTS at flowering stage showed more serious influence on grain yield than at grain filling stage. High temperature stress showed negative effects on harvest index. It might be helpful to provide valuable information for crop simulation models to capture the effects of high temperature stress on rice, and evaluate the high temperature risk.展开更多
Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose an...Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose and fructose content of tomato's fruit were increased but sucrose content was decreased with fruit growth and development. In different stages, carbohydrate content of tomato fruit in the treatment 3 was the highest, in the treatment 2 was higher, and in the other treatments was the lowest. SS(sucrose synthase)activity was decreased but SPS(sucrose phosphate synthase)activity was increased with development of tomato. SS and SPS activity were increased but acid invertase and neutral invertase activity of ripe stage were decreased under deficit irrigation. Glucose and fructose content were increased in leaves of tomato under water deficit. Soluble sugars, organic acid and the ratio of sugar/acid in tomato fruits were increased and dry matter accumulation of plant was enhanced under water deficit. But the growth of fruits upside the plant and its dry matter accumulation were badly affected under water stress.展开更多
Post-silking high temperature is one of the abiotic factors that affects waxy maize(Zea mays L. sinensis Kulesh) growth in southern China. We conducted a pot trial in 2016–2017 to study the effects of post-silking da...Post-silking high temperature is one of the abiotic factors that affects waxy maize(Zea mays L. sinensis Kulesh) growth in southern China. We conducted a pot trial in 2016–2017 to study the effects of post-silking daytime heat stress(35°C) on the activities of enzymes involved in leaf carbon and nitrogen metabolisms and leaf reactive oxygen species(ROS) and water contents. This study could improve our understanding on dry matter accumulation and translocation and grain yield production. Results indicated that decreased grain number and weight under heat stress led to yield loss, which decreased by 20.8 and 20.0% in 2016 and 2017, respectively. High temperature reduced post-silking dry matter accumulation(16.1 and 29.5% in 2016 and 2017, respectively) and promoted translocation of pre-silking photoassimilates stored in vegetative organs, especially in leaf. The lower leaf water content and chlorophyll SPAD value, and higher ROS(H2O2 and O2^-·) content under heat stress conditions indicated accelerated senescent rate. The weak activities of phosphoenolpyruvate carboxylase(PEPCase), Ribulose-1,5-bisphosphate carboxylase(Ru BPCase), nitrate reductase(NR), and glutamine synthase(GS) indicated that leaf carbon and nitrogen metabolisms were suppressed when the plants suffered from a high temperature during grain filling. Correlation analysis results indicated that the reduced grain yield was mainly caused by the decreased leaf water content, weakened NR activity, and increased H2O2 content. The increased accumulation of grain weight and post-silking dry matter and the reduced translocation amount in leaf was mainly due to the increased chlorophyll SPAD value and NR activity. Reduced PEPCase and Ru BPCase activities did not affect dry matter accumulation and translocation and grain yield. In conclusion, post-silking heat stress down-regulated the leaf NR and GS activities, increased the leafwater loss rate, increased ROS generation, and induced pre-silking carbohydrate translocation. However, it reduced the post-silking direct photoassimilate deposition, ultimately, leading to grain yield loss.展开更多
基金supported by the National Natural Science Foundation of China(42101382 and 42201407)the Shandong Provincial Natural Science Foundation China(ZR2020QD016 and ZR2022QD120)。
文摘The accurate simulation of regional-scale winter wheat yield is important for national food security and the balance of grain supply and demand in China.Presently,most remote sensing process models use the“biomass×harvest index(HI)”method to simulate regional-scale winter wheat yield.However,spatiotemporal differences in HI contribute to inaccuracies in yield simulation at the regional scale.Time-series dry matter partition coefficients(Fr)can dynamically reflect the dry matter partition of winter wheat.In this study,Fr equations were fitted for each organ of winter wheat using site-scale data.These equations were then coupled into a process-based and remote sensingdriven crop yield model for wheat(PRYM-Wheat)to improve the regional simulation of winter wheat yield over the North China Plain(NCP).The improved PRYM-Wheat model integrated with the fitted Fr equations(PRYM-Wheat-Fr)was validated using data obtained from provincial yearbooks.A 3-year(2000-2002)averaged validation showed that PRYM-Wheat-Fr had a higher coefficient of determination(R^(2)=0.55)and lower root mean square error(RMSE=0.94 t ha^(-1))than PRYM-Wheat with a stable HI(abbreviated as PRYM-Wheat-HI),which had R^(2) and RMSE values of 0.30 and 1.62 t ha^(-1),respectively.The PRYM-Wheat-Fr model also performed better than PRYM-Wheat-HI for simulating yield in verification years(2013-2015).In conclusion,the PRYM-Wheat-Fr model exhibited a better accuracy than the original PRYM-Wheat model,making it a useful tool for the simulation of regional winter wheat yield.
文摘[Objectives]This study was conducted to investigate the effects of slow-release nitrogen fertilizer on dry matter accumulation and translocation of summer maize.[Methods]With Zhoudan 9 as the test variety,six different treatment were set up:blank control(CK1),slow-release urea 75 kg/hm^(2)(C1),slow-release urea 150 kg/hm^(2)(C2),slow-release urea 225 kg/hm^(2)(C3),slow-release urea 300 kg/hm^(2)(C4)and ordinary urea 300 kg/hm^(2)(CK2),to study the change law of dry matter accumulation and translocation in summer maize.[Results]Treatment slow-release urea 225 kg/hm^(2)(C4)showed summer maize yield,dry matter translocation between organs,grain contribution rate and proportion of grain dry matter in the full ripe stage higher than other treatments.Considering the weight loss and cost factors,slow-release urea 225 kg/hm^(2)(C3)could be recommended as the fertilizing amount for summer maize.[Conclusions]This study provides theoretical reference for rational selection of fertilizers for reducing fertilizer application and increasing fertilizer efficiency,and for production of summer maize in Shajiang black soil region.
基金supported by the project of National Key Research and Development Program of China(2016YFD0300301 and 2017YFD0300603)The 2115 Talent Development Program of China Agricultural University。
文摘Lodging is a critical constraint to yield increase.There appear to be tradeoffs between yield formation and lodging resistance in maize.Hypothetically,it is feasible to reduce lodging risk as well as increase grain yield by optimizing dry-matter allocation to different organs under different environments.A three-year field experiment was conducted using four maize cultivars with differing lodging resistances and five growing environments in 2018–2020.Lodging-susceptible(LS)cultivars on average yielded more than lodging-resistant(LR)cultivars when lodging was not present.The yield components kernel number per ear(KN)and thousand-kernel weight(TKW)were both negatively correlated with lodging resistance traits(stalk bending strength,rind penetration strength,and dry matter weight per internode length).Before silking,the LR cultivar Lishou 1(LS1)transported more assimilates to the basal stem,resulting in a thicker basal stem,which reduced dry matter allocation to the ear and in turn KN.The lower KN of LS1 was also due partly to the lower plant height(PH),which increased lodging resistance but limited plant dry matter production.In contrast,the LS cultivars Xianyu 335(XY335)and Xundan 20(XD20)produced and allocated more photoassimilates to ears,but limited dry matter allocation to stems.After silking,LS cultivars showed higher TKW than LR cultivars as a function of high photoassimilate productivity and high assimilate allocation to the ear.The higher lodging resistance of LS1 was due mainly to the greater assimilate allocation to stem after silking and lower PH and ear height(EH).High-yielding and high-LR traits of Fumin(FM985)were related to optimized EH and stem anatomical structure,higher leaf productivity,low assimilate demand for kernel formation,and assimilate partitioning to ear.A high presilking temperature accelerated stem extension but reduced stem dry matter accumulation and basal stem strength.Post-silking temperature influences lodging resistance and yield more than other environmental factors.These results will be useful in understanding the tradeoffs between KN,KW,and LR in maize and environmental influences on these tradeoffs.
基金Supported by the Research and Development Plan of Applied Technology in Heilongjiang Province(GA19B104)。
文摘The high water content of corn grain at harvest is a challenge in Northeast China,where the growing season is short.Using a dehydrating agent before harvest can help corn seeds dehydrate quickly.The dry matter accumulation and nutrient quality of maize were systematically studied by field experiments and instrumental analysis using maize varieties of different maturities as test materials.The results showed that the accumulation of dry matter was enhanced by an increased dosage of a dehydrating agent.When the dehydrating agent dosage reached 1800 mL•hm-2,the dry matter accumulation of early-maturing varieties increased by 24.1 g,and the water content decreased by 8.08%.Different maize varieties were treated with the same dose;early-maturing varieties showed significant effects on grain dry matter accumulation,and kernel dry matter accumulation increased by 7%.The effects of different doses on grain dehydration were obvious,and the effects on different maize varieties varied.Medium-ripening maize varieties showed the most significant effect,with a 19.5%reduction in water content.The effects of dehydrating agent doses on maize yield,grain nutrient quality and seed germination rate were not significant.Therefore,a dehydrating agent promoted the accumulation of dry matter in grain and accelerated the rapid dehydration.
文摘Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangeland on relative frequency, dry matter yield and nutritive value of dominant grasses in an area invaded by Euryops floribundus. A plot of 2.5 ha was measured and the boundaries demarcated using tape measure and steal pins, the plot was further divided into two subplots of 1ha each which were 5 m apart. One subplot was fenced and protected from grazing livestock, while one subplot was grazed continuously and not fenced. Three parallel belt transects of 100 m × 2 m with 3 m apart were laid out in both subplots. Woody plants occurring within the transects were identified and recorded to determine density. In each subplot, a 0.25 m<sup>2</sup> quadrant measuring was thrown randomly to take detailed records on plant species, relative frequency of species and herbage biomass. Four dominant species at the two sites were harvested to determine the nutritive value. Results indicate that grazing exclusion (GE) facilitates grass species diversity, subsequently sixteen and thirteen grasses species were recorded in the GE and uncontrolled grazed (UG) sites, respectively. Eragrostis chloromelas (21.7%), and Themeda triandra (13.2%) had high relative frequencies in the GE site. Highest biomass production was recorded in the GE site (1400 kg·ha<sup>-1</sup>) compared to UG site (1102 kg·ha<sup>-1</sup>). Crude protein content was relatively lower at UG site (5.4% - 5.8%) as compared to GE site (7.2% - 7.8%). It was concluded that, GE showed a positive impact on a relative frequency (%), dry matter yield and crude protein content. UG creates a conducive environment for Euryops recruitment. Further studies are required to examine the impact of GE in long-term trial setup.
文摘Landscape urbanization broadly affects ecosystems in coastal watersheds, but, until now, the influence of nonpoint source urban inputs on dissolved organic matter (DOM) amount, composition, and source is poorly understood. To understand how DOM composition varied with urbanization, fluorescence excitation-emission matrices (EEMs) were determined for urban and non-urban waters from upstream to downstream sites along three adjacent coastal watersheds that flow into the Mediterranean Sea. Two humic DOM fluorescent components (humic-like and fulvic-like peaks) and two proteinic components (tyrosine-like and tryptophane-like peaks) were identified by EEM fluorescence. The results indicated that urbanization had an important influence on DOM concentration and composition, with urban waters having a high degree of DOM variation due to different land uses surrounding each body of water. Urban waters show a higher DOM fluorescence index (FI), the highest fluorescence intensity of protein-like manifested also by BIX values, and a lower value of the humification index (HIX) than non-urban waters which were dominated by allochthonous inputs. In addition, the EEM was compared in dry and wet season where higher DOM amounts and FI appeared in summer due to autochthonous production coming from algae growth compared to allochthonous input from rainfall dominated in wet season. The concentration of DOC increased from upstream to downstream for the three rivers, especially Beirut River. The increase in DOC values was observed in both dry and wet seasons by 39 and 19 times respectively compared to upstream (0.93 - 0.91 mgC/L).
文摘The pictures from the James Webb Space Telescope (JWST) suggest that massive galaxies were already at the beginning of the expansion of the Universe because there was too short time to create them. It is consistent with the new cosmology presented within the Scale-Symmetric Theory (SST). The phase transitions of the initial inflation field described in SST lead to the Protoworld—its core was built of dark matter (DM). We show that the DAMA/LIBRA annual-modulation amplitude forced by the change of the Earth’s velocity (i.e. baryonic-matter (BM) velocity) in relation to the spinning DM field in our Galaxy’s halo should be very low. We calculated that in the DM-BM weak interactions are created single and entangled spacetime condensates with a lowest mass/energy of 0.807 keV—as the Higgs boson they can decay to two photons, so we can indirectly detect DM. Our results are consistent with the averaged DAMA/LIBRA/COSINE-100 curve describing the dependence of the event rate on the photon energy in single-hit events. We calculated the mean dark-matter-halo (DMH) mass around quasars, we also described the origin of the plateaux in the rotation curves for the massive spiral galaxies, the role of DM-loops in magnetars, the origin of CMB, the AGN-jet and galactic-halo production, and properties of dark energy (DE).
基金Supported by the"11th Five-Year Plan"Significant Key Program of Guizhou Province[Guizhou Technology and Agriculture Co-word(2000)1109]Graduate Student Innovation Fund Project of Guizhou University[(2006)009]~~
文摘[Objective] The aim of the research was to find the optimal nitrogen application rate, density and seedling age for no-tillage rape in seedling stage. [Method] With the D-optimal quadratic regression design for three factors, the 310 scheme was designed to study the effects of nitrogen application rate, density and seedling age on dry matter accumulation of no-tillage rape in seedling stage. [Result] With the increase of nitrogen application rate, density and seedling age, the dry matter content appeared like a parabola, increasing firstly and then declining. The change of nitrogen application rate caused greater influence than that of density and seedling age; the interaction effects between nitrogen application rate and density were greater than that between nitrogen application rate and seedling age as well as between density and seedling age. [Conclusion] Considered comprehensively, the dry matter content of no-tillage rape in seedling stage reached the highest level (4 768.2 kg/hm2) when the nitrogen application rate, the density and the seedling age were 195 kg/hm2, 93 000 plants/hm2 and 33 d, respectively.
基金Supported by Science&Technology Innovation of Sichuan Characteristic AgricultureProvincial Breeding Key Project of the 12th Five Year Plan (No.2011yzgg-13-02-01)+2 种基金Sichuan Academy of Agricultural Sciences (2011LWJJ-008)Seed Industry Innovation and Transformation Project (2011JYGC10-027-02)Modern Agricultural Technology System Project (No.CARS-22)~~
文摘In this paper, the effect of different fertilizer treatments on the main indexes of growth and development and dry matter accumulation of perennial mulberry, which is cut and pruned in summer, were studied with ‘3414’ field experiment design. The results showed that N, P, and K at proper amounts could promote mulberry growth and development, improve its dry matter content, increase its dry matter accumulation. The effects of N, P, K on leaf yield per plant were respectively expressed as follows: N2 N3 N1 N0 , P2 P1 P3 P0 , K2 K1 K3 K0 . It can be concluded that the recommended fertilizer amounts of dry matter accumulations in mulberry leaf were 694.36 kg/hm2 of N, 198.15 kg/hm2 of P, and 274.26 kg/hm2 of K and the dry matter achieved the maximum at 8 045.04 kg/hm2 . The recommended fertilizer amounts of accumulated dry matter in branch were 1 000.05 kg/hm2 of N, 242.04 kg/hm2 of P, and 218.01 kg/hm 2 of K, and the dry matter achieved the maximum at 5 969.05 kg/hm2 . The recommended fertilizer amount in young shoots were 883.76 kg/hm2 of N, 204.48 kg/hm2 of P and 426.59 kg/hm2 of K and dry matter achieved the maximum at 1 410.24 kg/hm2 . This paper could provide reference for the construction of highly-qualified mulberry field in Sichuan hilly area.
文摘[Objective] This study was conducted to investigate the effects of application modes of potassium fertilizer on sorghum grain yield and dry matter accumulation. [Method] Sorghum hybrids Jiza 305 and Jiza 87 were used as materials, and four treatments were designed (Ko: applying potassium at 0 kg/hm^2, K1: applying potassium as base fertilizer at 120 kg/hm^2, K2: applying potassium as base fertilizer at 90 kg/hm^2 and as additional fertilizer at 30 kg/hm^2, and K3: applying potassium as base fertilizer at 60 kg/hm^2 and as additional fertilizer at 60 kg/hm^2) to investigate the effects of application modes of potassium fertilizer on dry matter accumulation and grain yield, so as to determine the best application mode of potassium fertilizer. [Result] The results showed that after the application of potassium, the leaf area, dry matter accumulation, grain starch content, yield and economic coefficient of sorghum plants were improved. The leaf area values of the two sorghum cultivars showed the order of K0〈K1〈K2〈K3. The economic coefficients were in order of K0〈 K3〈K2〈K1. The amounts of dry matter accumulation, grain starch contents and grain yields showed the order of K0〈K3〈K1〈K2. For Jiza 305, the grain yields of K1, K2 and K3 were higher than that of Ko by 9.3%, 15.6% and 9.3%, respectively. As to Jiza 87, the grain yields of K1, K2 and K3 were higher than that of K0 by 8.1%, 12.5% and 8.1%, respectively. [Conclusion] Comprehensively, the best application method was 90 kg of potassium as base fertilizer and 30 kg of potassium as additional fertilizer per hectare.
基金Supported by National Natural Science Foundation of China(31301379)Jiangsu Agriculture Science and Technology Innovation Fund(JASTIF),(CX(13)2028)+2 种基金The Earmarked Fund for Modern Agro-industry Technology Research System(CARS-11-C03)Jiangsu Provincial Science and Technology Support Program(BE2013437)Natural Science Foundation of Jiangsu Province(BK20130716)~~
文摘Using three orange-fleshed sweetpotato varieties as experimental materials,16 economic traits at 60 d,75 d,90 d,105 d,120 d and 135 d after planting were measured,so as to revealing the dynamic variations of β-carotene and dry matter accumulation in roots and their relationships with economic traits in orangefleshed sweetpotato.The results showed that the dynamic variations of β-carotene accumulation in tubers varied hugely among different varieties.Interesting,the βcarotene content of all three varieties showed a significant decrease after 120 d,while the dry matter content of them performed a similar "fluctuation-type".Correlation analysis indicated that β-carotene content of three orange-fleshed sweetpotato varieties had no significant correlation with dry matter content and photosynthetic parameters,but the correlation with other economic traits also varied among varieties.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201303129)National Science and Technology Project for Bump Crop(2011BAD16B05)Scientific Research Foundation of Sichuan Agricultural University~~
文摘To clarify the effects of mechanical sowing and transplanting on dry mat- ter production of middle-season hybrid rice, a two-factor split plot design was used to study the effects of different sowing and transplanting methods and their interac- tion with the seedling number per hill or seeding time on dry matter accumulation, distribution and transformation of F You 498, a middle-season hybrid rice variety, under field conditions in 2012 and 2013. The results showed that there was a marked effect of the sowing and transplanting methods and their interaction with the seedling number per hill or seeding time on dry matter accumulation, distribution and transformation. The total population dry matter accumulation of the treatments with mechanical direct seeding (MDS) and machine-based transplanting (MT) was lower than that of the treatment with traditional manual transplanting (TMT). How- ever, MDS had higher dry matter accumulation and accumulating rate in the joint- ing-earing stage,and maintained higher stem-sheath exportation, export rate and transformation than MT and TMT; MT had higher dry matter accumulation and ac- cumulating rate in the heading-maturity period than MDS and TMT. Moreover, the treatments with low seedling number per hill or early seeding enhanced the assimi- lation of dry matter after heading,the ratio of dry matter accumulation after earing to biomass yield and the contribution rate of dry matter accumulation after earing, and a reasonable early sowing was favorable to increase the harvest index of middle- season hybrid rice under mechanical sowing and transplanting conditions.
基金Supported by Key Program of the National Natural Science Foundation of China(61233006)Key Science and Technology Program of Shanxi Province(20130311010-1)
文摘[Objective] This study aimed to investigate the growth and development and dry matter production and allocation of greenhouse tomato in North China. [Method] With tomato cultivar 'Jinguo No.l' as the experimental material, the ex- periments were conducted in a solar greenhouse located in Taigu, Shanxi (37o25' N, 112o25' E) from March to July, in 2014 and 2015. [Result] The plant height, leaf number, leaf area and dry matter production of greenhouse tomato increased lin- early with the increased days after transplantation, and their growth rates were 2.74 cm/d, 0.32 leaf/d, 70 cm2/d and 9.4 g/(m2.d), respectively. The fruit dry weight also showed a linear relationship with the plant dry weight. After fruit setting, the fruit dry weight was increased by about 0.69 g when the plant dry weight was increased by 1 g. The allocation proportions of dry matter in tomato roots, stems and leaves de- clined significantly from plant flowering to fruiting, while the proportion of fruit dry weight in plant dry weight increased significantly, exceeding 60%. There was a strong linear relationship between dry matter production of tomato and effective cu- mulative temperature (sum of temperature higher than 10 ^(3) in the solar green- house, and the dry matter production was increased by about 0.73 g/m2 when the effective cumulative temperature was increased by one unit. The dry matter produc- tion of tomato plant also showed a strong linear relationship with photosynthetic ac- tive radiation (PAR) in the greenhouse, and about 3.4 g of dry matter was synthe- sized per unit (M J) of PAR. [Conclusion] Extending the growing period and improv- ing the temperature and light conditions could increase the dry matter production of tomato.
基金Supported by Scientific and Technological Development Plan of Shandong Province(2014GNC113001)Open Fund for National Key Laboratory of Crop Biology(2014KF11)
文摘[Objective] This study aimed to investigate the effects of different planting and irrigation patterns on water consumption characteristics and dry matter produc- tion and allocation of winter wheat. [Method] With high-yield winter wheat cultivar Jimai 22 as the experimental material, field experiment was conducted during 2008- 2010. A total of 3 planting patterns were designed, uniform row, wide-narrow row and furrow. Under each planting pattern, total four irrigation patterns were designed, no irrigation (Wo), irrigation at jointing state (Wl), irrigation at jointing and anthesis stages (W2) and irrigation at jointing, anthesis and milking stages (W3), and the irri- gation amount per treatment was all 60 mm. [Result] Under the three planting pat- terns, with the increased irrigation amount, the total water consumption of the exper- imental field increased; the proportion of irrigation in the total water consumption in- creased, and that of soil water consumption in the total water consumption de- creased significantly. Compared with W0 treatment, various irrigation treatments sig- nificantly increased the post-anthesis dry matter accumulation in wheat plants; with the increased irrigation amount, the grain yield under the three planting patterns all increased, while the water use efficiency (WUE) decreased. Under the same irriga- tion conditions, compared with other two planting patterns, furrow planting increased the total water consumption of the experimental field, increased the proportion of soil water consumption in the total water consumption, and improved the WUE and wheat grain yield. [Conclusion] Under the experimental conditions, considering both wheat grain yield and WUE, furrow planting with moderately deficit irrigation at joint- ing and anthesis stages is more suitable for the winter wheat production in North China Plain.
文摘In order to select the suitable soil for transplanting tobacco in Hunan to- bacco growing areas, pot experiment was conducted to study the effects of different transplanting nutdent soils on the growth and dry matter accumulation of tobacco. The results indicated that the treatments of transplanting with nutrition soils were better than the control group. For the underground part, transplanting nutrient soil could effectively improve the root activity of tobacco plants, and increase root volume, root surface area, total root length, as well as the number of root tips and the number of root branches. For the aboveground part, transplanting nutrient soil could remarkably improve the plant height, stem girth, leaf number and maximum leaf area, and could simultaneously significantly increase the dry matter accumulation. By comparison, peat + mushroom residue + saw dust + straw powder + bicchar + root promoting nutrient solution was the most effective treatment, and the effect of sole application of nutrient solution was limited. In conclusion, transplanting with nutrition soil could effectively promote the growth and dry matter accumulation of tobacco.
基金Supported by the National Transformation Project for Agriculture Science and Technology Achievements(2011GB2C300011)the National Science and Technology Funds for Agriculture during the Twelfth Five-year Plan(2011BAD35B06-4)~~
文摘[Objective] The aim was to discuss the group dry matter accumulation and economic benefits under the patterns of intercropping maize (Zea mays L.) with soy-bean [Glycine max (L.) Merril ]. [Methods] Zhengdan-958 and Luhuang-1 were used as the testing breeds to study the effects of intercropping patterns on dry matter accumulation and transportation of maize and soybean in Huang-huai-hai. [Results] For maize, the dry matter accumulation amounts per hectare of intercropping was significant higher than that of the monoculture patterns, especial y after silking, when it reached extremely level; while for soybean, the dry matter accumulation amounts before flowering and after flowering of monocropping were al significantly higher than that of the intercropping patterns. For both maize and soybean, the transfer amounts of monocropping were al significantly or extremely significantly higher than that of intercropping; and the transfer ratio of maize intercropping was 0.59% higher than that of maize monocropping, while for soybean, it was 4.74% higher. Fitted dry matter accumulation with Logistic equation, it showed that the difference in maximum dry matter accumulation rate between maize monocropping and intercropping reached significant level, while for soybean, the maximum dry matter accumulation rate and its appearance time as wel as duration time between intercropping and monocropping were al reached significant level. The total land equivalent ratio of intercropping was 1.30. From yield and output value, the total yield of intercropping were 10.97 t/hm2, 0.64% and 326.85% higher than monocropping of maize and soy-bean, respectively. The total output value of intercropping was 25 796.23 yuan/hm2, respectively 12.67% and 104.68% higher than of maize and soybean monocropping. [Conclusion] The study lays a basis for improving grain yield and economic benefits.
基金the National Key Basic Research Support Foundation(NKBRSF)of China(No.G1999011708) the Guangxi University Science funds,China(No.1701).
文摘Spring wheat (Triticum aestivum L. cv. Dingxi No. 8654) was treated with twoconcentrations of atmospheric CO_2 (350 and 700 μmol mol^(-1)), two levels of soil moisture(well-watered and drought) and five rates of nitrogen fertilizer (0, 50, 100, 150, and 200 mgkg^(-1) soil) to study the atmospheric CO_2 concentration effect on dry matter accumulation and Nuptake of spring wheat. The effects of CO_2 enrichment on the shoot and total mass depended largelyon soil nitrogen level, and the shoot and total mass increased significantly in the moderate to highN treatments but did not increase significantly in the low N treatment. Enriched CO_2 concentrationdid not increase more shoot and total mass in the drought treatment than in the well-wateredtreatment. Thus, elevated CO_2 did not ameliorate the depressive effects of drought and nitrogenstress. In addition, root mass decreased slightly and root/shoot ratio decreased significantly dueto CO_2 enrichment in no N treatment under well-watered condition. Enriched CO_2 decreased shoot Ncontent and shoot and total N uptake; but it reduced root N content and uptake slightly. Shootcritical N concentration was lower for spring wheat grown at 700 μmol mol^(-1) CO_2 than at 350μmol mol^(-1) CO_2 in both well-watered and drought treatments. The critical N concentrations were16 and 19 g kg^(-1) for the well-watered treatment and drought treatment at elevated CO_2 and 21 and26 g kg^(-1) at ambient CO_2, respectively. The reductions in the movement of nutrients to theplant roots through mass flow due to the enhancement in WUE (water use efficiency) and the increasein N use efficiency at elevated CO_2 could elucidate the reduction of shoot and root Nconcentrations.
基金supported by the National Basic Research Program of China (2010CB951302-2)the National Natural Science Foundation of China (51109214 and 31101074)
文摘Climate change is recognized to increase the frequency and severity of extreme temperature events. At flowering and grain filling stages, risk of high temperature stress (HTS) on rice might increase, and lead to declining grain yields. A regulated cabinet experiment was carried out to investigate effects of high temperature stress on rice growth at flowering and grain- filling stages. Results showed that no obvious decrease pattern in net photosynthesis appeared along with the temperature rising, but the dry matter allocation in leaf, leaf sheath, culm, and panicle all changed. Dry weight of panicle decreased, and ratio of straw to total above ground crop dry weight increased 6-34% from CK, which might have great effects on carbon cycling and green house gas emission. Grain yield decreased significantly across all treatments on average from 15 to 73%. Occurrence of HTS at flowering stage showed more serious influence on grain yield than at grain filling stage. High temperature stress showed negative effects on harvest index. It might be helpful to provide valuable information for crop simulation models to capture the effects of high temperature stress on rice, and evaluate the high temperature risk.
基金supported by the National Natural Science Fundation of China(30170640)Natural Science Fund of Liaoning Provice,China(20022080).
文摘Four irrigation treatments were designed with 2,4,6 and 8 d intervals to irrigate, respectively. Watering was stopped when the reading of the moisture tension sensor reached zero. The results indicated that glucose and fructose content of tomato's fruit were increased but sucrose content was decreased with fruit growth and development. In different stages, carbohydrate content of tomato fruit in the treatment 3 was the highest, in the treatment 2 was higher, and in the other treatments was the lowest. SS(sucrose synthase)activity was decreased but SPS(sucrose phosphate synthase)activity was increased with development of tomato. SS and SPS activity were increased but acid invertase and neutral invertase activity of ripe stage were decreased under deficit irrigation. Glucose and fructose content were increased in leaves of tomato under water deficit. Soluble sugars, organic acid and the ratio of sugar/acid in tomato fruits were increased and dry matter accumulation of plant was enhanced under water deficit. But the growth of fruits upside the plant and its dry matter accumulation were badly affected under water stress.
基金supported by the National Key Research and Development Program of China (2016YFD0300109 and 2018YFD0200703)the National Natural Science Foundation of China (31771709 and 31471436)the Priority Academic Program Development of Jiangsu Higher Education Institutions, China
文摘Post-silking high temperature is one of the abiotic factors that affects waxy maize(Zea mays L. sinensis Kulesh) growth in southern China. We conducted a pot trial in 2016–2017 to study the effects of post-silking daytime heat stress(35°C) on the activities of enzymes involved in leaf carbon and nitrogen metabolisms and leaf reactive oxygen species(ROS) and water contents. This study could improve our understanding on dry matter accumulation and translocation and grain yield production. Results indicated that decreased grain number and weight under heat stress led to yield loss, which decreased by 20.8 and 20.0% in 2016 and 2017, respectively. High temperature reduced post-silking dry matter accumulation(16.1 and 29.5% in 2016 and 2017, respectively) and promoted translocation of pre-silking photoassimilates stored in vegetative organs, especially in leaf. The lower leaf water content and chlorophyll SPAD value, and higher ROS(H2O2 and O2^-·) content under heat stress conditions indicated accelerated senescent rate. The weak activities of phosphoenolpyruvate carboxylase(PEPCase), Ribulose-1,5-bisphosphate carboxylase(Ru BPCase), nitrate reductase(NR), and glutamine synthase(GS) indicated that leaf carbon and nitrogen metabolisms were suppressed when the plants suffered from a high temperature during grain filling. Correlation analysis results indicated that the reduced grain yield was mainly caused by the decreased leaf water content, weakened NR activity, and increased H2O2 content. The increased accumulation of grain weight and post-silking dry matter and the reduced translocation amount in leaf was mainly due to the increased chlorophyll SPAD value and NR activity. Reduced PEPCase and Ru BPCase activities did not affect dry matter accumulation and translocation and grain yield. In conclusion, post-silking heat stress down-regulated the leaf NR and GS activities, increased the leafwater loss rate, increased ROS generation, and induced pre-silking carbohydrate translocation. However, it reduced the post-silking direct photoassimilate deposition, ultimately, leading to grain yield loss.